Buckles and buckle release systems are frequently used to secure harnesses, safety restraints, and parachutes. Parachute harnesses, for example, include a buckle having a buckle release system for releasing the harness from the canopy of the parachute. Several different buckle release systems are known in the art.
U.S. Pat. No. 3,986,234 to Frost et al, discloses a releasable fastener for securing together two straps. A link is included for attachment to one of the straps. The link takes the form of a plate-like strike with a pair of spaced-apart locking lugs that define locking notches. The lugs cooperate with a pair of spaced-apart locking pins. Bifurcated levers secured to the upper ends of the locking pins serve to rotate the locking-pins in response to the movement of a slide. A pivotal latch is also included. The latch must be pivoted prior to moving the slide.
The buckle of Frost may suffer from the drawback that a large amount of force is needed in order to move the slide and release the parachute riser straps. The force required to move the slide dramatically increases to the extent that one or more of the straps is under tension, as may be the case when a parachute is deployed. The level of force required to move the slide may preclude a user from releasing the mechanism or may preclude the user from releasing the mechanism with one hand.
A further buckle release design is disclosed in U.S. Pat. No. 5,857,247 to Warrick et al. Warrick discloses a buckle release system for the manual or automatic release of a crewmember harness. This buckle has a frame that receives a cooperating tang that is secured to a portion of the harness. A tang assembly secures the buckling member in the frame. A latch that pivots between a closed position and an open position holds the tang assembly. The latch is intended to prevent the inadvertent release of the buckling member from the frame. A lever that includes a cavity holds a free end of the latch. During operation, the lever is moved to an open position in order to release the latch.
However, like other buckles, the buckle disclosed in Warrick may not open and release the harness under some difficult or extreme conditions. Failure of the buckle to open and release can be hazardous to the wearer of the harness. For example, a parachute canopy may exert a substantial force on the harness when the conditions are windy and/or when the canopy is being dragged through water. If the buckle fails to release when needed, or if the wearer is otherwise unable to activate the release, the aircraft personnel could be dragged along the ground or through water due to the force on the canopy. This could place the wearer in great danger of receiving significant bodily injury.
An additional buckle release system is disclosed in U.S. Pat. No. 6,763,557 to Clark et al., the contents of which are fully incorporated herein by reference. Clark discloses a buckle release system for releasing a parachute canopy from a harness. The buckle includes both a lock lever, a manual release lever, a spring biased catch and a latch positioned in a frame. A slide member is provided that operates to hold the latch in a locked position and prevents a buckling member from being released when the buckle is in a locked position. The lock lever is provided to prevent the unintended release of the manual release lever and thus a premature release of the parachute canopy from a harness.
However, the lock lever of Clark often encounters significant aerodynamic and inertial forces both before and after parachute deployment. On some occasions, these forces may cause the premature release of the lock lever. Although such an event would not, in and of itself, cause the premature release of the parachute canopy, it does reduce the available safety factor. Namely, if both the lock lever and the release lever were prematurely opened, the result could be a premature release of the canopy.
Accordingly, a need exists for a buckle with a buckle release system that can withstand and operate under difficult operating environments. There also exists a need for a buckle release system that is not prone to premature or accidental release and that can be released while under load.